[PATCH 3/8] powerpc/slb: Define macros for the bolted slots

[Anshuman Khandual <khandual@linux.vnet.ibm.com>]

This patch defines macros for all the three bolted SLB slots. This also
renames the 'create_shadowed_slb' function as 'new_shadowed_slb'.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
---
 arch/powerpc/mm/slb.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index faf9f0c..701a57f 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -25,6 +25,11 @@
 #include <asm/udbg.h>
 #include <asm/code-patching.h>
 
+enum slb_slots {
+	LINEAR_SLOT	= 0, /* Kernel linear map  (0xc000000000000000) */
+	VMALLOC_SLOT	= 1, /* Kernel virtual map (0xd000000000000000) */
+	KSTACK_SLOT	= 2, /* Kernel stack map */
+};
 
 extern void slb_allocate_realmode(unsigned long ea);
 extern void slb_allocate_user(unsigned long ea);
@@ -74,7 +79,7 @@ static inline void slb_shadow_clear(unsigned long entry)
 	get_slb_shadow()->save_area[entry].esid = 0;
 }
 
-static inline void create_shadowed_slbe(unsigned long ea, int ssize,
+static inline void new_shadowed_slbe(unsigned long ea, int ssize,
 					unsigned long flags,
 					unsigned long entry)
 {
@@ -103,16 +108,16 @@ static void __slb_flush_and_rebolt(void)
 	lflags = SLB_VSID_KERNEL | linear_llp;
 	vflags = SLB_VSID_KERNEL | vmalloc_llp;
 
-	ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, 2);
+	ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, KSTACK_SLOT);
 	if ((ksp_esid_data & ~0xfffffffUL) <= PAGE_OFFSET) {
 		ksp_esid_data &= ~SLB_ESID_V;
 		ksp_vsid_data = 0;
-		slb_shadow_clear(2);
+		slb_shadow_clear(KSTACK_SLOT);
 	} else {
 		/* Update stack entry; others don't change */
-		slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, 2);
+		slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, KSTACK_SLOT);
 		ksp_vsid_data =
-			be64_to_cpu(get_slb_shadow()->save_area[2].vsid);
+			be64_to_cpu(get_slb_shadow()->save_area[KSTACK_SLOT].vsid);
 	}
 
 	/* We need to do this all in asm, so we're sure we don't touch
@@ -125,7 +130,7 @@ static void __slb_flush_and_rebolt(void)
 		     "slbmte	%2,%3\n"
 		     "isync"
 		     :: "r"(mk_vsid_data(VMALLOC_START, mmu_kernel_ssize, vflags)),
-		        "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, 1)),
+		        "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, VMALLOC_SLOT)),
 		        "r"(ksp_vsid_data),
 		        "r"(ksp_esid_data)
 		     : "memory");
@@ -151,7 +156,7 @@ void slb_vmalloc_update(void)
 	unsigned long vflags;
 
 	vflags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmalloc_psize].sllp;
-	slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
+	slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, VMALLOC_SLOT);
 	slb_flush_and_rebolt();
 }
 
@@ -312,19 +317,19 @@ void slb_initialize(void)
 	asm volatile("isync":::"memory");
 	asm volatile("slbmte  %0,%0"::"r" (0) : "memory");
 	asm volatile("isync; slbia; isync":::"memory");
-	create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, 0);
-	create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
+	new_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, LINEAR_SLOT);
+	new_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, VMALLOC_SLOT);
 
 	/* For the boot cpu, we're running on the stack in init_thread_union,
 	 * which is in the first segment of the linear mapping, and also
 	 * get_paca()->kstack hasn't been initialized yet.
 	 * For secondary cpus, we need to bolt the kernel stack entry now.
 	 */
-	slb_shadow_clear(2);
+	slb_shadow_clear(KSTACK_SLOT);
 	if (raw_smp_processor_id() != boot_cpuid &&
 	    (get_paca()->kstack & slb_esid_mask(mmu_kernel_ssize)) > PAGE_OFFSET)
-		create_shadowed_slbe(get_paca()->kstack,
-				     mmu_kernel_ssize, lflags, 2);
+		new_shadowed_slbe(get_paca()->kstack,
+				     mmu_kernel_ssize, lflags, KSTACK_SLOT);
 
 	asm volatile("isync":::"memory");
 }
-- 
2.1.0